All 3 pictures show how something changes through time.
The candle will burn and the wax will melt and the candle will become smaller.
The sand timer will empty and fill back up every time it is turned.
Leaves will fall from the tree and change colour.
The leaf shows us changes in colour as time passes.
The leaf changes shape and size as it gets older it shrivels up and the texture changes.
All 3 pictures show time and change.